The primary objectives of the Project are to breed and maintain congenic, transgenic or inbred mice in a barrier facility. Up to 600 breeding pairs (or trios) of congenic or inbred mice and 6, 500 offspring are to be accommodated. The project requires detailed record keeping, genetic testin and animal care must be meticulous, in accord with the NIH Guide for the Care and Use of Laboratory Animals, and under a veterinarian's supervision.